1. Copyright Notice
A portion of the disclosure of this patent document contains material that is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever.
2. Field of the Invention
Embodiments of the present invention relate, in general, to network management. More specifically, embodiments of the present invention relate to methods and systems for monitoring Management Information Base (MIB) for use with network management protocols.
3. Description of the Background Art
A Network Management Station (NMS) monitors and administers network devices in a network using application layer protocols such as a Simple Network Management Protocol (SNMP). The NMS gathers information about the changes in the network devices to monitor and administer the network devices. The information about the changes such as configuration and behavioral changes in a network device, and response of network devices to a network change, constitute management information of the network devices. A software module such as an SNMP agent running on the network device provides management information of the network device to the NMS using Management Information Bases (MIBs). The MIBs are present in the network device. An MIB includes a large number of variables known as MIB objects. The NMS monitors the objects lead to changes in the network devices and consequently, the changes in the network.
According to conventional methods, the NMS may use asynchronous and synchronous monitoring mechanisms, to monitor the changes in the MIB objects. One such example of asynchronous monitoring is an SNMP-trap mechanism. In the SNMP-trap mechanism, the network device sends SNMP traps to the NMS if the MIB objects are changed. However, it is possible that in some cases, the SNMP traps are not received by the NMS. As a result, the SNMP-trap mechanism is not completely reliable. Further, the SNMP-trap mechanism is applicable when a trap for a change in the MIB object is defined at the time of defining the MIB object. Moreover, the SNMP trap-mechanisms require highly available NMS.
In another asynchronous monitoring mechanism, the NMS may use Remote Monitoring (RMON) to monitor the changes in the MIB objects. However, the RMON uses a large memory of the network devices for monitoring the MIB objects. As a result, the RMON is not suitable for monitoring a huge list of the MIB objects.
In another conventional method, the NMS may use SNMP polling as a synchronous monitoring mechanism for monitoring the changes in the MIB objects. In SNMP polling, the NMS periodically polls the MIB objects. The periodic polling of each MIB object results in detecting changes in the MIB objects that have occurred between two subsequent time-periods. SNMP polling is more reliable in comparison to asynchronous mechanisms. Moreover, SNMP polling does not require highly-available NMS. However, the SNMP polling of each MIB object generates a large amount of SNMP traffic in the network. Moreover, the SNMP polling of each MIB object is not useful when no changes are detected in the MIB objects. As a result, the method of SNMP polling of each MIB object has to be optimized to avoid the generation of a large amount of traffic in the network.